Pent-1-ene

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 - 27 August 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study under GLP with full documentation.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

The temperature for the reference study lay in a range of 22.6 to 22.7 °C and therefore higher than stated in the guidelines. No critical immobility occurred during the test. Non-critical deviation.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

The temperature for the reference study lay in a range of 22.6 to 22.7 °C and therefore higher than stated in the guidelines. No critical immobility occurred during the test. Non-critical deviation.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Medium: M4-Medium (recipe of ELENDT; 293.80 mg/L CaCl2*2H2O, 123.30 mg/L MgSO4*7H2O, 64.80 mg/L NaHCO3, 5.80 mg/L KCl in deionised water).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUSS
- Strain: Berlin
- Origin: Umweltbundesamt Berlin
- Animal Husbandry: Daphnia magna is bred in the LAUS GmbH throughout the year. The animals are kept for the use in toxicity tests. They multiply by parthenogenesis, thus being genetically identical. The husbandry is performed similar to the method described in EN ISO 6341, following SOP 115 002 01 („Zucht und Hälterung von Daphnia magna STRAUS“), edition 9, adopted 27. Apr. 2007.
- Vessels glass beakers, nominal volume 2 l
- Medium M4-Medium (recipe of ELENDT)
- Food unicellular green algae (Desmodesmus subspicatus)
- Medium renewal twice a week
- Photo period 16/8 hours, using neon tubes
- Temperature 20 +/- 2 °C

- Age at study initiation: 0 - 23 h
- Method of breeding: parthenogenesis
- Feeding during test: None

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

The immobilised animals were also counted after 24 h

Post exposure observation period:

None

Hardness:

2.50 mmol (250 mg CaCO3/L)

Test temperature:

22 +/- 1 °C

pH:

7.8 +/- 0.2

Dissolved oxygen:

At t = 0 h: 8.2 +/- 0.0 mg/L in the test media
At t = 48 h: 7.6 - 8.8 mg/L in the test media

Nominal and measured concentrations:

Test item, nominal concentrations: 10, 18, 32, 56 and 100 mg/L
Test item, measured concentrations: see Table 3 of chapter "Any other information on results incl. tables"
Positive control, nominal concentrations: 1.0, 1.25, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Test item: closed glass flasks. Positive Control: glass beakers
- Type: closed
- Material, size, headspace, fill volume: Test item: total volume 310 mL, fill volume 310 mL. Positive Control: nominal volume: 50 mL
- Aeration: no
- No. of organisms per vessel: Test item and positive control: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): n.a. as no vehicle used
- Biomass loading rate: n.a.

OTHER TEST CONDITIONS
- Photoperiod: 16/8 hours, using neon tubes
- Light intensity: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilisation

Reference substance (positive control):

yes

Remarks:

K2Cr2O7 (CAS No. 7778-50-9)

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

34 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Results based on the concentrations measured at the end of the test (initial concentration were much too low, probably due to insufficient homogenisation)

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

110 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Results based on the concentrations measured at the end of the test (initial concentration were much too low, probably due to insufficient homogenisation)

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 140 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Results based on the concentrations measured at the end of the test (initial concentration were much too low, probably due to insufficient homogenisation)

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

20 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Results based on the concentrations measured at the end of the test (initial concentration were much too low, probably due to insufficient homogenisation)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

35 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Results based on the concentrations measured at the end of the test (initial concentration were much too low, probably due to insufficient homogenisation)

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

140 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Results based on the concentrations measured at the end of the test (initial concentration were much too low, probably due to insufficient homogenisation)

Details on results:

The estimation of the EC50 was accomplished using the software Origin(TM). The data were evaluated using sigmoidal fit on a linear-logarithmic scale.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50/LC50: The 24h-EC50i of potassium dichromate was determined as 1.6 mg/L, lying within the de-manded range of 0.6 – 1.7 mg/L.

STABILITY OF THE TEST SUBSTANCE IN THE MEDIUM

The stability in test medium was determined by spiking 104.5 mL test medium with 1.5 µL (conc. 9.2 mg/L) and 16 µL (conc. 98 mg/L) Pentene-1. At t = 0; after 1 and 2 days storage at room temperature, respectively, 1 mL test solution (two replicates) was collected. A sample volume of 50 µL was taken from the headspace and measured threefold via GC/FID. The solutions in the vials were temperate for 15 minutes at 20°C before measurement. The measured areas at the end of the storage period were compared with the mean areas from the beginning. For each concentration three replicates were analysed.

The results are presented in the following table:

Table 1     Stability in Test Medium at concentration 9.2 mg/L

Time	Area1_1	Area1_2	Area2_1	Area2_2	Area3_1	Area3_2	Areamean
0 days	37.51	46.76	48.20	47.92	57.46	39.86	46.29
1 days	41.55	44.65	37.52	42.24	42.12	48.98	42.84
2 days	31.95	30.15	28.85	30.20	33.43	44.48	33.18
Recovery after 1 day							92.6 %
Recovery after 2 days							71.7 %

 

Table 2     Stability in Test Medium at concentration 98 mg/L

Zeit	Area1_1	Area1_2	Area2_1	Area2_2	Area3_1	Area3_2	Areamean
0 days	470.97	382.18	494.63	403.22	520.86	435.22	451.18
1 days	317.86	286.72	446.11	343.55	342.56	382.63	353.24
2 days	324.85	285.36	336.85	319.83	355.96	333.29	326.02
Recovery after 1 day							78.3 %
Recovery after 2 days							72.3 %

 

Due to the high volatility of the test item, no better stability could be determined.

RESULTS OF THE MAIN STUDY WITH THE TEST ITEM

- Measured concentrations

The measured concentration after 48 hours was in a range of 75 – 140 % of the nominal concentration. With the exception of the lowest concentrated treatment, the measured concentrations at the beginning were much too low. This was believed to be due to insufficient homogenisation. Therefore, one treatment with a nominal concentration of 121 mg/L was prepared in the same fashion as in the main study (only without daphnia) and analysed at t = 0 h, 1 h and 4 h. After 1 h, 92% of the nominal concentration were recovered. Therefore, the determination of the biological results was based on the measured concentrations at the end of the test.

The measured concentrations for treatment and control are given in the following table:

Table 3     Measured Concentrations Main Study

Nominal Concentration in mg/L	Measured Concentration in mg/L		% of Nominal Concentration
	0 h	48 h	0 h	48 h
0	< LOQ	< LOQ	< LOQ	< LOQ
10	11.2	12.1	112	121
18	7.2	19.5	40	109
32	5.9	33.7	18	105
56	9.8	41.8	17	75
100	15.7	139.9	16	140

 

LOQ = Limit of quantification (1.2 mg/L)

- Immobilities

In the control, none of the daphnia died or showed any signs of abnormal behaviour throughout the test (see table below).

Table 4     Immobilities

Nominal Concentration in mg/L	Immobility 24 hours					Immobility 48 hours
	abs.				in %	abs.				in %
0	0	0	0	0	0	0	0	0	0	0
10	0	0	0	0	0	0	0	0	0	0
18	0	0	0	0	0	0	0	0	0	0
32	0	0	0	2	10	0	5	0	4	45
56	1	1	3	3	40	4	2	5	3	70
100	3	5	1	2	55	5	5	5	5	100

Validity criteria fulfilled:

yes

Conclusions:

Acute toxicity of 1-Pentene to Daphnia magna was determined under GLP according to OECD 202 guideline. The experiment was valid according to the validity criteria.
The 48h-EC50 is 35 mg/L.

Executive summary:

Due to the volatility of the test item, the test was performed in a closed system and the nominal load of test item was directly injected into the test vessels.

The main study was performed using five concentrations ranging from 10 to 100 mg/L. Twenty daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised daphnia were counted.

Three concentrations showed toxicity ranging from 45 and 100% immobilisation. None of the animals were immobilised in the control.

The 24 h-EC50_iof potassium dichromate was tested in a current reference test. The value was determined as 1.6 mg/L, lying within the demanded range of 0.6 – 1.7 mg/L.

 

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using GC. The measured values at the end of the test were in the expected range, but at the beginning, the measured values are too low. This was due to insufficient homogenisation in the completely filled test vessels: for verification, one treatment with the concentration 120 mg/L was prepared in the same fashion as in the main study (only without daphnia) and analysed at t = 0 h, 1 h and 4 h. After 1 h 92% of the nominal concentration were recovered. Therefore, the scheduled test item concentrations were stated as stable under test conditions and the determination of the biological results was based on the measured concentrations at the end of the test.

The following results were determined for the test item Pentene-1 (species: Daphnia magna).

 

24h-NOEC = 34 mg/L
48h-NOEC = 20 mg/L
24h-EC50_i= 115 mg/L
48h-EC50_i= 35 mg/L
48h EC100 = 140 mg/L

Description of key information

Short-term toxicity to aquatic invertebrates

OECD 202, GLP, key study, validity 2

48h-EC50 (Daphnia magna)= 35 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

35 mg/L

Additional information

Due to the volatility of the test item, the test was performed in a closed system and the nominal load of test item was directly injected into the test vessels.

The main study was performed using five concentrations ranging from 10 to 100 mg/L. Twenty daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised daphnia were counted.

Three concentrations showed toxicity ranging from 45 and 100% immobilisation. None of the animals were immobilised in the control.

The 24 h-EC50_iof potassium dichromate was tested in a current reference test. The value was determined as 1.6 mg/L, lying within the demanded range of 0.6 – 1.7 mg/L.

 

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using GC. The measured values at the end of the test were in the expected range, but at the beginning, the measured values are too low. This was due to insufficient homogenisation in the completely filled test vessels: for verification, one treatment with the concentration 120 mg/L was prepared in the same fashion as in the main study (only without daphnia) and analysed at t = 0 h, 1 h and 4 h. After 1 h 92% of the nominal concentration were recovered. Therefore, the scheduled test item concentrations were stated as stable under test conditions and the determination of the biological results was based on the measured concentrations at the end of the test.

The following results were determined for the test item Pentene-1 (species:Daphnia magna).

 

24h-NOEC = 34 mg/L
48h-NOEC = 20 mg/L
24h-EC50_i= 115 mg/L
48h-EC50_i= 35 mg/L
48h EC100 = 140 mg/L